Almost half of all colorectal and cervical cancer cases and about a third of breast cancer cases are diagnosed at a late stage, when treatment is more likely to fail. Early detection could make a life-saving difference for millions of people around the world.
Polymerase Chain Reaction (PCR) has long been the standard technique used by researchers seeking to better understand the relationship between DNA mutations and the development of cancer, however PCR is limited in its ability to detect small amounts of mutated DNA within the large amounts of normal DNA present in human tissue samples. Therefore, current cancer detection through PCR has required invasive tissue biopsies, only possible late in the progression of the disease.
Digital PCR promises to break through this barrier by allowing much smaller concentrations of mutated DNA to be detected earlier with less invasive procedures.
This new technology will detect minute amounts of mutated DNA indicative of cancer with a simple blood sample.
Digital PCR achieves this by splitting the sample into thousands or millions of partitions and analyzing each part individually. In short, it finds the needle in the haystack by looking at each piece of hay individually.
When RainDance Technologies approached Continuum, they already had a proven picodroplet platform that could be used for digital PCR applications but they required a method to transform the technology into an intuitive commercial product. The technology flows the sample through microscopic channels in a disposable plastic chip along with a special oil that breaks the sample into an emulsion of ten million droplets, each measuring precisely 20 microns in diameter—one quarter the width of a human hair. The system then analyzes each droplet with a laser-based detector to read multi-color fluorescent labels that bind selectively to mutated or normal DNA.
Continuum assembled a multi-disciplinary team of engineers and designers with experience in a variety of industries to develop this technology into a simple, user-friendly device to be made commercially available to labs around the world. Working together, Continuum and RainDance Technologies created the revolutionary RainDrop™ Digital PCR System, a more sensitive, scalable and precise solution which is 500 to 10,000 times better than existing methods.
Inspired by a complex set of ideas utilized in the aerospace industry, the team turned to a technology for making fluid passages in aluminum plates, often used for routing oil in aircraft engines. When applied to the RainDrop instrument, it greatly simplified the complex fluidic pathways to precisely drive flow within the disposable chips. Experience with ink-jet printers was applied for understanding precision motion control to develop a reliable, low-cost mechanism to position the laser spot precisely within channels on the chip to read droplets as they flow past at a rate of ten thousand per second.